Diagram showing the three lobes of a trilobite. Diagram courtesy of
Sam Gon III http://www.trilobites.info
The name "trilobite" (meaning "three-lobed") is not based on the body sections cephalon, thorax and pygidium, but rather on the three longitudinal lobes: a central axial lobe, and two symmetrical pleural lobes that flank the axis.
File:Trilobite lobes-en.svg ist eine vektorisierte Version dieses Bildes. Diese sollte an Stelle des Rasterbildes verwendet werden, sofern sie nicht schlechter ist.